Conversion of the human blood group H antigen to A antigen in vitro

Abstract

A-transferase (N-acetylgalactosaminyl transferase) was purified from human group A plasma using Sepharose 4B affinity chromatography. Human anti-A antibodies were purified from human serum by adsorption to an immunosorbent column and heat elution in order to detect the A antigen. Conditions appropriate for the development of the A antigen on O red cells were examined and several buffer systems were found to be equally effective. Expression of the developed A antigen was found to be similar to that on group A red cells, indicating that the system in vitro has similar activity to the system in vivo. The H antigen from human saliva was coupled to Sepharose 4B or adsorbed to a nitrocellulose membrane. The A antigen was able to be developed on these materials by the action of group A-transferase. The procedures enabled the identification in vitro of sugar-transferase activities which can be useful in studies within the A,B,H antigen system or other carbohydrate antigen system.

Blood Group Antigen Recognition via the Group A Streptococcal M Protein Mediates Host Colonization

“…The human blood group antigen classification system is based on three glycan structures, A, B and H, with precursors lacto- N -tetraose (LNT; Gal-β-1,3-GlcNAc-β-1,3-Gal-β-1,4-Glc), lactosamine type 1 (Galβ1-3GlcNAc), and lactosamine type 2 (Galβ1-4GlcNAc) forming the major backbone of all three antigens (4). Host gene expression of α-1,2-fucosyltransferase enables synthesis of H antigen, which can be further transformed by N -acetylgalactosaminyl-transferase or d -galactosyl-transferase to produce A and B antigens, respectively (5, 6). Expression of A, B, and H antigens on epithelial cell surfaces and secretion into extracellular fluid is dependent on expression of the Se( FUT2 ) gene encoding fucosyl-transferase 2, which facilitates secretion of the corresponding blood group antigens by mucin-secreting goblet cells (1).…”